He redeemed us in order that the blessing given to Abraham might come to the Gentiles through Christ Jesus, so that by faith we might receive the promise of the Spirit. Galatians 3:14 NIV
Why is “faith” mentioned in this process?
Because God wants “Him in us” to be our choice. God wants fellowship.
As God He could have designed “Him in us” from the start. He could have made a world filled with people full of the Holy Spirit—an automatic extension of Himself—much like a bunch of puppets.
But, God wants people who make the choice first to invite Him to be part of their lives and then to delight in listening to His Holy Spirit for guidance, encouragement and life strategy.
That’s where faith comes in. By faith we make these choices.
It’s a great deal for God and for man. God has made for Himself a ka-zillion friends and we get the best and wisest friend of all.